Fuel Impact on Boiler Concept - outlook , Värme- och Kraftkonferensen 2012 Morgondagens energisystem Juha Sarkki Edgardo Coda

Transcription

1 Fuel Impact on Boiler Concept - outlook , Värme- och Kraftkonferensen 2012 Morgondagens energisystem Juha Sarkki Edgardo Coda

2 Presentation Outline Solid Biomass as Energy Source & Circulating Fluidized Bed Technology Fuel characterization Boiler Design Features for Biomass Firing Key References for Biomass Firing Clean Biomass Fuels Challenging Biomass Fuels 1

3 Biomass as Energy Source & Market Drivers Biomass has an important role in reducing the environmental effects (CO 2 ) of energy production Biomass fuel market has changed to global and makes possible large scale power generation of biomass alone In addition to the traditional clean and recycled biomasses, the trend today shows increasing interest to applying agricultural biomass & waste For the boiler supplier is important to understand bio fuel origin and treatment processes as well as the actual ranges of fuel and ash properties CFB is IDEAL TECHNOLOGY for large scale power generation for broad range of biomass alone or co-firing in larger fossil fired power plants! 2

4 Key Advantages of CFB for Biomass Firing Fuel flexibility is a special advantage Wide range for biomass fuels Mixes of wood, agro, waste, etc Mixes of biomass fuels, coal Excellent emission performance Inherently low emissions No DeSOx / DeNOx plants required High availability & competitive price 3

5 CFB Fuel Flexibility & Biomass Fuels 4

6 Fuel Flexibility in CFB Coal Anthracite Bituminous Subbituminous Lignite Wood Residue Bark Chips Sawdust Forest Residue Recycled Wood Tire Derived Fuel Solid Recovered Fuel Waste Coal Bituminous Gob Anthracite Culm Coal Slurry Petroleum Coke Delayed Fluid Peat Agricultural Waste Straw Olive Waste Sunflower Husk Rapeseed Dried Fruits... Sludge Paper mill De-inking Municipal Waste Paper Gas Natural Off gases Oil Oil Shale 5

7 Biomass Properties Timber Timber Saw Bagasse Straw Peat Recycled RDF pellets chips dust briquette pellets wood fluff Moisture % Lower Heating Value MJ/kg 17 7,5-13, ,7 9, Bulk Density kg/m Energy density MWh/m3 3 0,55 0,45-0,7 2,9 2,7 0,9 1,4 0,4 Ash % ds 0,9 0,4-5,3 0,4-0, , S % ds <0,1 <0,1 <0,05 <0,05 0,01-0,03 0,22 0,1 0,1-0,5 Cl % ds <0,03 <0,05 <0,03 <0,03 0,1-0,8 0,02-0,06 0,1 0,3-1,2 Alkali % ds 0,1-0,3 0,1-0,3 0,1-0,3 0,4-0,7 0,3-1,7 0,1 0,1-0,5 0,4-1 P % ds <0,05 <0,05 <0,04 <0,05 0,05-0,8 <0,35 <0,3 <0,5 High concentrations of alkalis and chlorine increase risk for agglomeration, fouling and corrosion

8 Prediction tools for fuel effects and corrosion estimation 10 Agglomeration Fouling Corrosion Probability Index A. - agro biomass Bitumin. Stem A. 1 A. 2 A. 3 A. 4 A. 5 A. 6 A. 7 Straw A. 8 A. 9 Olive Waste LOW MEDIUM HIGH VERY HIGH WOOD HERBACEOUS FRUIT COAL BIOMASS Agglomeration, Fouling and Corrosion probabilities for selected fuels based on FW AFC model 7

9 Boiler Design Features for Biomass Firing 8

10 Factors Effecting for Boiler Concept Fuel Characterization Physical & Chemical characteristics Fouling characteristics Corrosion characteristics Plant Requirements Utility / Industrial Steam data Emissions Legistlation Investment Factors Investment cost Operation cost Fuel flexibility Availability 9

11 Design Features for challenging fuels Integrated Water/Steam Cooled Solid Separator and Return Leg Features to control Fouling & Corrosion - Correct flue gas temperature Features to control Agglomeration & Fouling - Correct design for convective heat transfer surfaces Effective temperature control Conservative flue gas velocity Possibility to use Additives with worst quality agros Active Bed Material During Operation: - Fuel quality management - FW SmartBoiler datalog & Diagnostic tools Step Grid Final SH & RH as INTREX 10

12 Additives and alternative bed materials against Agglomeration, Fouling and Corrosion Schematic representation of mechanisms observed between fuel ash, bed materials, and additives non-fouling (FA) fouling/non-corrosive fouling/corrosive limestone Sulfur kaolinite agglomerating coating melt non-agglomerating (BA) 11

13 The role of alloying elements against fire-side Clinduced corrosion >600 C Mean oxide layer thickness [μm] 400 Alloy A (18.5% Cr, 10% Ni) Alloy B (25% Cr, 20% Ni) T = 650 C 350 Alloy C (22.5% Cr, 25% Ni) Alloy D (23%Cr, 50.8% Ni) T = 520 C Log (Cl wt-% in deposit) Laboratory corrosion test results High Cl concentration Deposit from commercial CFB co-firing high share of agro with coal (408 hours) High Cr, or high total alloying elements do not guarantee low corrosion Other material properties such as stabilizing elements and crystallographic structure gain a bigger role at temperatures > 600 C 12

14 Materials availability for higher efficiency boilers Materials for higher steam temperatures (up to 600 C) in biomass and waste fired plant. A review of present knowledge Annika Stålenheim and Pamela Henderson 13

15 References for Biomass Firing 14

16 Biomass CFB, Västerås Increased capacity with wider fuel range 180 MW th (originally 157 MW th ), 170/39 bar, 540/540 C Fuel mix Forest residues [%] LHV 35 Wood chips [%] LHV 10 Bark [%] LHV 5 Saw dust [%] LHV 5 Peat [%] LHV 15 Willow [%] LHV 5 Demolition wood [%] LHV 25 Emissions 6%O 2, dry NOx [mg/m 3 n] 65 NH 3 -slip [ppm] 5 SO 2 [mg/m 3 n] 130 CO [mg/m 3 n] 210 Dust [mg/m 3 n] 20 15

17 Large Scale CFB for Clean Biomass (CHP) 125MW e Kaukas, Finland Owner: Kaukas Kaukaan Voima Oy - Owned by Lappeenrannan Energia Oy (46%) and Pohjolan Voima Oy (54%). Located at UPM-Kymmene paper mill site in Lappeenranta, Finland Combined heat and power plant (CHP) Lappeenranta Project - Investment drivers: More effective utilization of paper mill byproducts Replacing gas with cheaper biomass fuel for Lappeenranta City s electricity and district heat production (earlier 100% gas) Commercial Operation February 2010

18 Large Scale CFB for Clean Biomass (CHP) 125MW e Kaukas, Finland 125 MW e-net, 110 MW DH, 149 kg/s, 115 bar(a), 550 C Fuel Biomass Peat Moisture [%] ar Ash [%] dry Nitrogen [%] dry Sulfur [%] dry LHV [MJ/kg] ar Performance Biomass Flue gas T exit [ C] 149 Boiler efficiency [%] 91 NOx [mg/m 3 n] 150 SO 2 [mg/m 3 n] 200 CO [mg/m 3 n] 200 Dust [mg/m 3 n] 20 The Power Plant was the World s largest user of solid biomass fuels in 2010! 17

19 Advanced Bio CFB Concept for 20%-w Agro 205MW e Polaniec, Poland World s Largest pure solids Biomass Fired Power Plant 80% wood chips & 20% Agro 447MW th, 535/535ºC, 127/20 bar(a) Polaniec Re-powering from Coal to Biomass Customer: GFD Suez Energia Polska S.A Contract Award 2/2010 Commercial operation 12/

20 Advanced Bio CFB Concept for 20%-w Agro 205MW e Polaniec, Poland 447 MW th, 190MW e, 535/535ºC, 127/20 bar(a) Fuel 80% Wood Chips & 20% AGRO (Straw, Sunflower etc) Moisture [%] ar 35.9 Ash [%] dry 2.8 Nitrogen [%] dry 0.25 Sulfur [%] dry 0.05 LHV [MJ/kg] ar 10.5 Emissions NOx [mg/m 3 n] 150 SO 2 [mg/m 3 n] 150 CO [mg/m 3 n] 50 Dust [mg/m 3 n] 20 19

21 Multifuel CFB for Waste and Clean Biomass (CHP) Igelsta (Söderenergi AB, Södertälje) 240 MW th, 73 MW e-net, 209 MW DH, 92 kg/s, 90 bar, 540 C Fuel Mix 1 Mix 2 Mix 3 Biomass [%] LHV Rec.wood [%] LHV REF pellets [%] LHV Moisture [%] ar Ash [%] dry Nitrogen [%] dry Sulfur [%] dry Chlorine [ppm] dry LHV [MJ/kg] ar Total plant efficiency ~110% LHV 90% HHV Emissions 6%O 2, dry NOx [mg/mj] 35* SO 2 [mg/m 3 n] 75 CO [mg/m 3 n] 50* Dust [mg/m 3 n] 10 NH 3 ppm 10 TOC [mg/m 3 n] 10 HCl / HF [mg/m 3 n] 10 / 1 Cd+Tl / Hg / HMs [mg/m 3 n] 0.05 / 0.05 / 0.5 PCDD+F [ng/m 3 n] 0.1 *) only at 100% load with Mix 1, 2, and 3 20

22 Advanced Bio CFB Technology with Pure Solid Biomass up to scale 600MW e with Sub-Critical Steam Parameters 568/566ºC, /43.6 bar(a) Market Prospects today up to MW e CFB Technology available up to 600MW e Natural Circulation Evaporator (~175bar) Once Through Benson evaporator (~ bar) Lower Investment cost in large scale High plant efficiency over the whole load range 21

23 Large Scale and High Efficiency Advanced Bio CFB Concept for 20-30%-w Agro with Clean Biomass up to scale 400MW e 568/566ºC, /43.6 bar(a) Natural Circulation available up to 400MWe (~179bar) Limiting factor for scale in EU is drum manufacturing capability (up to scale ~350MWe) Once Through Benson available up to 400MWe (~ bar) Lower Investment cost in scale ~ MWe Limiting factor for steam pressure is corrosion resistance of evaporator panel wall 22

24 Take Away,, Biomass has an important role in reducing the environmental effects of energy production. CFB technology is an ideal Technology to be used for power generation with broad range of solid biomass fuels, comprising of 20 % agro biomass in the recent projects commissioned this year. CFB Technology with pure biomass firing available up to 600 MW e scale. 23

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